Calculation of Node Important Degree for Traffic Network Considering Cascading Failure

To find and manage key nodes in traffic network and prevent large scale network failure,the calculating method of node important degree based on the cascading failure behaviors was built.First,a cascading failure model for traffic network based on bi-level network was posed.In this model,(1) the upper travel network and lower road network are influenced each other;(2) initial capacities of nodes and links were given,these initial capacities do not affected by but affect initial flow;(3) travel time is used to describe status of links;(4) capacity of links may change because of downstream congestion.Second,the evaluation method of node important degree of traffic network considering cascading failure was proposed based on node deletion.The congestion status of cascading failure network was used to describe the node important degree,and algorithm procedures were designed to estimate the important degree of all nodes.The experiment analysis shows that network structure and traveler behaviors have significant influence on node important degree.